The generals of the allies now undertook an enterprise, which, in the opinion of the French generals, savoured of rashness and inconsiderate self-sufficiency. This was the siege of Lisle, the strongest town in Flanders, provided with all necessaries, stores of ammunition, and a garrison reinforced with one and twenty battalions of the best troops in France, commanded by mareschal de Boufflers in person. But these were not the principal difficulties which the allies encountered. The enemy had cut off the communication between them and their magazines at Antwerp and Sas-Fan-Ghent; so that they were obliged to bring their convoys from Ostend along a narrow causeway, exposed to the attack of an army more numerous than that with which they sat down before Lisle. On the thirteenth of August it was invested on one side by prince Eugene, and on the other by the prince of Orange-Nassau, stadtholder of Friesland; while the duke of Marlborough encamped at Hel-chin, to cover the siege. The trenches were opened on the twenty-second day of August, and carried on with that vigour and alacrity which is always inspired by victory and success. The dukes of Burgundy and Vendôme being now joined by the duke of Berwick, resolved, if possible, to relieve the place; and made several marches and counter-marches for this purpose. Marlborough being apprized of their intention, inarched out of his lines to give them battle, being reinforced by a considerable body of troops from the siege, including Augustus king of Poland, and the landgrave of Hesse, as volunteers; but the enemy declined an engagement, and the allies returned to their camp, which they fortified with an intrenchment. On the seventh day of September, the besiegers took by assault the counterscarp of Lisle, after an obstinate action, in which they lost a thousand men. The French generals continued to hover about the camp of the confederates, which they actually cannonaded; and the duke of Marlborough again formed his army in order of battle; but their design was only to harass the allies with continual alarms, and interrupt the operations of the siege. They endeavoured to surprise the town of Aeth, by means of a secret correspondence with the inhabitants; but the conspiracy was discovered before it took effect. Then they cut off all communication between the besiegers and the Schelde, the banks of which they fortified with strong intrenchments, and a prodigious number of cannon; so that now all the stores and necessaries were sent to the camp of the confederates from Ostend. On the twenty-first day of September, prince Eugene, who was in the trenches, seeing the troops driven by the enemy from a lodgement they had made on the counterscarp of the tenaille, rallied and led them back to the charge; but being wounded over the left eye with a musket-shot, he was obliged to retire, and for some days the duke of Marlborough sustained the whole command, both in the siege and of the covering army. On the twenty-third the tenaille was stormed, and a lodgement made along the covered way. Mareschal Boufflers having found means to inform the duke de Vendôme that his ammunition was almost expended, this general detached the chevalier de Luxembourg, with a body of horse and dragoons, to supply the place with gunpowder, every man carrying a bag of forty pounds upon the crupper. They were discovered in passing through the camp of the allies, and pursued to the barrier of the town, into which about three hundred were admitted; but a great number were killed by the confederates, or miserably destroyed by the explosion of the powder which they carried.
The next attempt of the French generals was to intercept a convoy from Ostend. The count de la Motte marched from Ghent, with about two and twenty thousand men, to attack this convoy, which was guarded by six thousand of the allies, commanded by major-general Webb. This officer made such an admirable disposition by the wood of Wynendale, and received the enemy with such a close fire, that, after a very warm action that lasted two hours, they retired in the utmost confusion, notwithstanding their great superiority in number, leaving six thousand men killed upon the field of battle; the loss of the allies not exceeding nine hundred and twelve officers and soldiers. This was the most honourable exploit performed during the whole war, and of such consequence to the confederates, that if the convoy had been taken, the siege must have been raised. The duke de Vendôme ordered the dikes between Bruges and Newport to be cut, so as to lay the whole country under water, in hopes of destroying the communication between Ostend and the camp of the confederates; and, after a regular siege, he took colonel Caulfield, and a body of British troops posted in the village of Leffinghen, by whose means the convoys had been forwarded to the duke of Marlborough. On the twenty-second of October, mareschal Boufflers desired to capitulate for the town of Lisle: next day the articles were signed: on the twenty-fifth the allies took possession of the place, and the mareschal retired into the citadel with the remains of his garrison, which, from twelve thousand, was reduced to less than the half of that number. A negotiation was begun for the surrender of the citadel; but Boufflers made such extravagant demands as were rejected with disdain. Hostilities were renewed on the twenty-ninth day of the month; and the earl of Stair was detached to provide corn for the army in the districts of Fumes and Dixmuyde. During these transactions, veldt-mareschal D’Auverquerque died at Roselser, in the sixty-seventh year of his age, after having, in above thirty campaigns, exhibited innumerable proofs of uncommon courage, ability, and moderation. The duke de Vendôme did not despair of obliging the confederates to abandon their enterprise: the French ministers at Rome and Venice publicly declared the allied army was cooped up in such a manner, that it must either raise the siege or be famished. The elector of Bavaria, with a detachment of ten thousand men, marched to Brussels, and attacked the counterscarp with incredible fury; but was repulsed by the garrison, under the command of general Paschal, and retired with precipitation, when he understood that the duke of Marlborough was in motion to relieve the place. This nobleman and prince Eugene no sooner understood the danger to which Brussels was exposed, than they marched with the covering army to the Schelde, which they passed in pontoons without opposition, notwithstanding the formidable works which the French had raised. They now abandoned them with precipitation, to the surprise of the confederates, who had laid their account with the loss of a thousand men in the attack. Having passed the river between Eskenaffe and Hauterive, as well as at other places, they marched to Oudenarde, where they received intelligence that the elector had retreated. Then prince Eugene returned to Lisle, and the duke of Marlborough proceeded to Brussels, where he was received with joy and acclamation. He afterwards took post at Oudenarde, so as to maintain a communication with prince Eugene.